xref: /linux/include/scsi/libiscsi.h (revision f24e9f586b377749dff37554696cf3a105540c94)
1 /*
2  * iSCSI lib definitions
3  *
4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5  * Copyright (C) 2004 - 2006 Mike Christie
6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
7  * Copyright (C) 2004 - 2005 Alex Aizman
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22  */
23 #ifndef LIBISCSI_H
24 #define LIBISCSI_H
25 
26 #include <linux/types.h>
27 #include <linux/mutex.h>
28 #include <scsi/iscsi_proto.h>
29 #include <scsi/iscsi_if.h>
30 
31 struct scsi_transport_template;
32 struct scsi_device;
33 struct Scsi_Host;
34 struct scsi_cmnd;
35 struct socket;
36 struct iscsi_transport;
37 struct iscsi_cls_session;
38 struct iscsi_cls_conn;
39 struct iscsi_session;
40 struct iscsi_nopin;
41 
42 /* #define DEBUG_SCSI */
43 #ifdef DEBUG_SCSI
44 #define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
45 #else
46 #define debug_scsi(fmt...)
47 #endif
48 
49 #define ISCSI_XMIT_CMDS_MAX	128	/* must be power of 2 */
50 #define ISCSI_MGMT_CMDS_MAX	32	/* must be power of 2 */
51 #define ISCSI_CONN_MAX			1
52 
53 #define ISCSI_MGMT_ITT_OFFSET	0xa00
54 
55 #define ISCSI_DEF_CMD_PER_LUN		32
56 #define ISCSI_MAX_CMD_PER_LUN		128
57 
58 /* Task Mgmt states */
59 #define TMABORT_INITIAL			0x0
60 #define TMABORT_SUCCESS			0x1
61 #define TMABORT_FAILED			0x2
62 #define TMABORT_TIMEDOUT		0x3
63 #define TMABORT_NOT_FOUND		0x4
64 
65 /* Connection suspend "bit" */
66 #define ISCSI_SUSPEND_BIT		1
67 
68 #define ISCSI_ITT_MASK			(0xfff)
69 #define ISCSI_CID_SHIFT			12
70 #define ISCSI_CID_MASK			(0xffff << ISCSI_CID_SHIFT)
71 #define ISCSI_AGE_SHIFT			28
72 #define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)
73 
74 struct iscsi_mgmt_task {
75 	/*
76 	 * Becuae LLDs allocate their hdr differently, this is a pointer to
77 	 * that storage. It must be setup at session creation time.
78 	 */
79 	struct iscsi_hdr	*hdr;
80 	char			*data;		/* mgmt payload */
81 	int			data_count;	/* counts data to be sent */
82 	uint32_t		itt;		/* this ITT */
83 	void			*dd_data;	/* driver/transport data */
84 	struct list_head	running;
85 };
86 
87 enum {
88 	ISCSI_TASK_COMPLETED,
89 	ISCSI_TASK_PENDING,
90 	ISCSI_TASK_RUNNING,
91 };
92 
93 struct iscsi_cmd_task {
94 	/*
95 	 * Becuae LLDs allocate their hdr differently, this is a pointer to
96 	 * that storage. It must be setup at session creation time.
97 	 */
98 	struct iscsi_cmd	*hdr;
99 	int			itt;		/* this ITT */
100 	int			datasn;		/* DataSN */
101 
102 	uint32_t		unsol_datasn;
103 	int			imm_count;	/* imm-data (bytes)   */
104 	int			unsol_count;	/* unsolicited (bytes)*/
105 	int			data_count;	/* remaining Data-Out */
106 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
107 	int			total_length;
108 	struct iscsi_conn	*conn;		/* used connection    */
109 	struct iscsi_mgmt_task	*mtask;		/* tmf mtask in progr */
110 
111 	/* state set/tested under session->lock */
112 	int			state;
113 	struct list_head	running;	/* running cmd list */
114 	void			*dd_data;	/* driver/transport data */
115 };
116 
117 struct iscsi_conn {
118 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
119 	void			*dd_data;	/* iscsi_transport data */
120 	struct iscsi_session	*session;	/* parent session */
121 	/*
122 	 * LLDs should set this lock. It protects the transport recv
123 	 * code
124 	 */
125 	rwlock_t		*recv_lock;
126 	/*
127 	 * conn_stop() flag: stop to recover, stop to terminate
128 	 */
129         int			stop_stage;
130 
131 	/* iSCSI connection-wide sequencing */
132 	uint32_t		exp_statsn;
133 
134 	/* control data */
135 	int			id;		/* CID */
136 	struct list_head	item;		/* maintains list of conns */
137 	int			c_stage;	/* connection state */
138 	/*
139 	 * Preallocated buffer for pdus that have data but do not
140 	 * originate from scsi-ml. We never have two pdus using the
141 	 * buffer at the same time. It is only allocated to
142 	 * the default max recv size because the pdus we support
143 	 * should always fit in this buffer
144 	 */
145 	char			*data;
146 	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */
147 	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */
148 	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */
149 
150 	/* xmit */
151 	struct kfifo		*immqueue;	/* immediate xmit queue */
152 	struct kfifo		*mgmtqueue;	/* mgmt (control) xmit queue */
153 	struct list_head	mgmt_run_list;	/* list of control tasks */
154 	struct list_head	xmitqueue;	/* data-path cmd queue */
155 	struct list_head	run_list;	/* list of cmds in progress */
156 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
157 	/*
158 	 * serializes connection xmit, access to kfifos:
159 	 * xmitqueue, immqueue, mgmtqueue
160 	 */
161 	struct mutex		xmitmutex;
162 
163 	unsigned long		suspend_tx;	/* suspend Tx */
164 	unsigned long		suspend_rx;	/* suspend Rx */
165 
166 	/* abort */
167 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
168 	struct iscsi_tm		tmhdr;
169 	struct timer_list	tmabort_timer;
170 	int			tmabort_state;	/* see TMABORT_INITIAL, etc.*/
171 
172 	/* negotiated params */
173 	int			max_recv_dlength; /* initiator_max_recv_dsl*/
174 	int			max_xmit_dlength; /* target_max_recv_dsl */
175 	int			hdrdgst_en;
176 	int			datadgst_en;
177 	int			ifmarker_en;
178 	int			ofmarker_en;
179 	/* values userspace uses to id a conn */
180 	int			persistent_port;
181 	char			*persistent_address;
182 
183 	/* MIB-statistics */
184 	uint64_t		txdata_octets;
185 	uint64_t		rxdata_octets;
186 	uint32_t		scsicmd_pdus_cnt;
187 	uint32_t		dataout_pdus_cnt;
188 	uint32_t		scsirsp_pdus_cnt;
189 	uint32_t		datain_pdus_cnt;
190 	uint32_t		r2t_pdus_cnt;
191 	uint32_t		tmfcmd_pdus_cnt;
192 	int32_t			tmfrsp_pdus_cnt;
193 
194 	/* custom statistics */
195 	uint32_t		eh_abort_cnt;
196 };
197 
198 struct iscsi_queue {
199 	struct kfifo		*queue;		/* FIFO Queue */
200 	void			**pool;		/* Pool of elements */
201 	int			max;		/* Max number of elements */
202 };
203 
204 struct iscsi_session {
205 	/* iSCSI session-wide sequencing */
206 	uint32_t		cmdsn;
207 	uint32_t		exp_cmdsn;
208 	uint32_t		max_cmdsn;
209 
210 	/* configuration */
211 	int			initial_r2t_en;
212 	int			max_r2t;
213 	int			imm_data_en;
214 	int			first_burst;
215 	int			max_burst;
216 	int			time2wait;
217 	int			time2retain;
218 	int			pdu_inorder_en;
219 	int			dataseq_inorder_en;
220 	int			erl;
221 	int			tpgt;
222 	char			*targetname;
223 
224 	/* control data */
225 	struct iscsi_transport	*tt;
226 	struct Scsi_Host	*host;
227 	struct iscsi_conn	*leadconn;	/* leading connection */
228 	spinlock_t		lock;		/* protects session state, *
229 						 * sequence numbers,       *
230 						 * session resources:      *
231 						 * - cmdpool,		   *
232 						 * - mgmtpool,		   *
233 						 * - r2tpool		   */
234 	int			state;		/* session state           */
235 	struct list_head	item;
236 	int			age;		/* counts session re-opens */
237 
238 	struct list_head	connections;	/* list of connections */
239 	int			cmds_max;	/* size of cmds array */
240 	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */
241 	struct iscsi_queue	cmdpool;	/* PDU's pool */
242 	int			mgmtpool_max;	/* size of mgmt array */
243 	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */
244 	struct iscsi_queue	mgmtpool;	/* Mgmt PDU's pool */
245 };
246 
247 /*
248  * scsi host template
249  */
250 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
251 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
252 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
253 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
254 			      void (*done)(struct scsi_cmnd *));
255 
256 /*
257  * session management
258  */
259 extern struct iscsi_cls_session *
260 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
261 		    int, int, uint32_t, uint32_t *);
262 extern void iscsi_session_teardown(struct iscsi_cls_session *);
263 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
264 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
265 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
266 			   enum iscsi_param param, char *buf, int buflen);
267 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
268 				   enum iscsi_param param, char *buf);
269 
270 #define session_to_cls(_sess) \
271 	hostdata_session(_sess->host->hostdata)
272 
273 /*
274  * connection management
275  */
276 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
277 					       uint32_t);
278 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
279 extern int iscsi_conn_start(struct iscsi_cls_conn *);
280 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
281 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
282 			   int);
283 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
284 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
285 				enum iscsi_param param, char *buf);
286 
287 /*
288  * pdu and task processing
289  */
290 extern int iscsi_check_assign_cmdsn(struct iscsi_session *,
291 				    struct iscsi_nopin *);
292 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
293 					struct iscsi_data *hdr,
294 					int transport_data_cnt);
295 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
296 				char *, uint32_t);
297 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
298 			      char *, int);
299 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
300 				char *, int);
301 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
302 			    uint32_t *);
303 
304 /*
305  * generic helpers
306  */
307 extern void iscsi_pool_free(struct iscsi_queue *, void **);
308 extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int);
309 
310 #endif
311